Birth defects affect 1 in every 33 babies at birth, and up to 1 in every 20 children by the time they are five years of age. The long term goal is to prevent birth defects and reduce their adverse consequences. Because most birth defects still have no identifiable cause, the Centers for Disease Control and Prevention established the National Birth Defects Prevention Study (NBDPS) in 1997. This population-based case control study represents a nationwide effort to identify causes of birth defects as a basis for primary prevention. The Utah Center for Birth Defects Research and Prevention joined this study in 2002. The Utah center uses the Utah Birth Defect Network, a population-based surveillance program, as the basis for identifying babies with birth defects. Building on the established infrastructure developed in Utah since joining the NBDPS, the overall objectives of this proposal are to expand the resource of epidemiological information and genetic data on birth defects, and to extend the Utah center's investigations on how environmental and genetic factors, alone or in combination, influence the risk for birth defects. The specific aims are to: (1) Ascertain and recruit a minimum of 300 eligible infants with birth defects ("cases") and 100 infants without birth defects ("controls") each year. Cases will be ascertained from the statewide population-based surveillance program. All cases will undergo expert review by a clinical geneticist. Healthy live born controls will be selected as a random sample of Utah's newborns from statewide birth certificates. (2) Interview study participants (i.e., mothers) and collect biological samples (DNA) from each family "trio" (mother, father, and baby). Mothers willing to participate will be interviewed using a computer-assisted telephone interview. If consent is given, DNA from family trios will be obtained from buccal (cheek cell) swabs, and additional DNA from newborn blood spots. (3) Analyze and disseminate surveillance data, identify environmental risk factors for birth defects, and create and initiate projects to find genetic risk factors for birth defects. In addition to analyzing and disseminating data on birth defect surveillance on an ongoing basis, the Utah center will develop and complete epidemiological and genetic studies on risk factors for birth defects using the collective NBDPS resource. The findings from the proposed project will provide the basis for developing strategies aimed at modifying risk factors for birth defects in the population. In doing so, the project will contribute to reducing the burden of birth defects and improving the chance that babies are born healthy, without birth defects.